Introduction of human mini-chromosome vector carrying human dystrophin gene into the mdx mice

点击翻译按钮获取中文摘要

Duchenne muscular dystrophy (DMD) is a severe X-linked recessive, progressive muscle-wasting disease caused by mutations in the DMD gene that encodes a 427-kDa cytoskeletal protein called dystrophin. The dystrophin gene is uniquely complex ; 79 exons spread, over approximately 2.5Mb of genomic region, with at least seven separate promoters. Multiple isoforms of dystrophin, thus formed, are expressed in muscle and non-muscle tissues at separate stages of development.In the present experiment, we have attempted to introduce whole dystrophin genomic region of the human X chromosome into the mdx mice, which is X chromosome-linked recessive myopathic mutants used as human models of DMD. At first, we have isolate embryonic stem cells from the mdx mice and established a new ES cell line, named mdx-1. The mdx-1 ES cells had the ability of forming viable germ line chimeras. Next, whole dystrophin genomic region of the human X chromosome was allowed to translocate, utilizing Cre-loxP system, into a stable human minichromosome vector, HAC-SC20. The dystrophin-cairying minichromosome was then transferred into the mdx-1 ES cells by microcell-mediated chromosome transfer technique. By injecting the ES cells into the mdx blastocysts, we have produced chimeric mice, in which human dystrophin gene might be expressing exclusively.